Dental casting appliance.



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E. R. STEALY. DENTAL CASTING APPLIANGE. APPLIUATION FILED SEPT. 24, 1903.

Patented Feb, 8, 1910.

?, 1,9'- I I Snowdon ELZA. R. STEALY, OF DUNLAP, IOWA.

DENTAL CSTING `LIPPLL'ANCIEL eraria- Specification of Letters latent.

Patenten ren., e. raro.

Application'iled September 24, 1908. Serial No. 454,512.

To all 'whom it may concern.'

y .investment ring ed for use in casting in ays, backings and crowns, etc., or any artificial dentures ofmetal commonly used in dentistry.

rFlic invention further consists in the novel construction and arrangement 0f the several parts essentially comprising means for creatv ing a vacuum, or introducing air under pressure within a reservoir adapted to be connected with an investment cupv constitutlng a suction or air chambfer for the reception of 'molds to be reproduced in metal.

ln casting certain metals into artificial dentures l find it expedient to employ a vac-. uum while in others compressed air would probably be more advantageously used. With this object in View and to` make the method optional, I have provided a reservoir common to both and by means of such an arrangement the appliance, with certain modifications may be used in various arts wherein the casting of metal is a feature.

' For a full understanding of the invention and the merits thereof and yalso to vac uire a knowledge of the details of constructlon of the means for effecting the result, reference is to be had to the following description and accompanying drawings, in which:

Figure l is a side elevation of the appliance partly in section. Fig. 2 is a side elevation of a modified form of appliance partly in section. Fig. 3' is an enlarged detail view of the investment cup. Fig. 4c is an enlarged detail view of a cup 'preferablyv used for investing and in some instances used for casting by compressed air. Fig. 5 is a longitudinal section showing the investment ring in position 'within the investment cup when casting with 'a vacuum; Fig. 6 is a longitudinal section showing the use of the when casting .with cmpressed air. I' v Corresponding and like parts are referred description and indicated to inthe followin the drawings by the same in all the views o reference characters.

Referring to the drawings, the numeral l designates a vacuum or compressed air reservoir of any desired construction or formation preferably supported upon legs 2 secured to a base 3 in any suitable manner, and provided with a gage 4 adapted to furnish readings of the pressure consequent upon the creation of a vacuum in said reservoir 0r upon the introduction of compressed air.

The numeral 5 designates a tube connected with the reservoir and provided with a threaded opening 6 at its opposite end arranged to -receive'and form an air tight joint fora pump 7 having a check valve on its lower end, located within thetube, and 8 designates a globe valve of ordinary construction by .means of which the tube is closed when the'pump is not in operation. The said pump 7 1s illustrated as adapted to toV operate by hand and detachably 'secured'.

within the end of the tube l5 to provide a simple means of substituting a suction for a force pump or vice versa, and as will be obvious any suitable means may be employed whereby a vacuum magy be created within the reservoir or" air introduced into said reservoir when desired.

A` tube 9 connects with th'ereservoir and opens therein and is provided with a transversely enlarged bore, as shown at 10, which is preferably ground to form an air tight` vjoint with the slightly taperingV stem 11 of an investment cup 12, and 13 designates a. globe valve in said tube designed to regulate the outward influence of the pressure uponv the contentsof the cup 12vwhen casting by vacuum or compressed air.

The asks or investment cups-12 are of various sizes and of any desired formation,

preferably oval, provided 'with a tumbler shaped body portlon 12 the sides of which i are ground or otherwise provided with a surface adapted to form anair tight joint when said tube `for the purpose of exerting the force of the pressure upon the contents of.v

the cup when casting by vacuum.

The numeral 1G designates a block pro-y Ament 18 is being formed and also when casting with compressed air, the said openings communicating with a longitudinal opening or recess 19 arranged for the escape of air from the stem of the cups.

20 designates a tube preferably composed of flexible material such as rubber, one. end of which is attached to the tubular stein 21 of the cup 14 and the opposite end attached to the tube 9. At the option of the operator the inlays etc., may be investedin a ring 22 (see Fig. 4) orovided with openings 23 near the bottom or the escape of air, and the cup 14 is placed over the end of said ring when casting with compressed air, as shown in Fig. 6. 1f it is desired to cast by vacuum the ring 22 is placed within the cup 12 as shown in Fig. 5, the operation in both instances being the same as if the investments had been formed in said cup. The internal formation of the investing cup is preferably round or oval with a fiat bottom or base, the interior side surface being ground to vform an air tight joint with the ground exterior surface of the ring 22 when said ring is placed Within the cup.

jF or casting dentures from low fusing metals a cup 24 of the same general formation as the cup 12 is preferably used, (Fig. 3) and said cup 12 is placed Within the larger cup containing the investment material.

' The wax or metal sprue25 is attached to the form 26 and extends Within the` opening in the stem of the cup 12.

In the practical operation of the applif ance when casting metals by vacuum, the investment composed of'silax :and plaster of paris mixed in Water is placed Within the cup 12 and While soft the Waxlinlay or pattern 26 attached to afwax or metal sprue 25 is forcedy into theinvestment material to forma mold. The investment is then allowed to dry and harden and the metal sprue is removed or the wax sprue (if Wax is used insteadof metal) and inlay melted out to form an opening andv cavity-for the introduction of molten metal.. 'Before the sprue and Wax inlay have been removed a slight depression in the investment is made around said sprue'for the purpose of holding the molten metal, when ready to proceed with the casting operation. rlhe steink of the cup 12 is placed in the tube 9 and the pressure consequent upon the vacuum within the reservoir created by the suction pump 7, is eX- erted simultaneously with the introduction yof the molten metal Within the opening left bythe Wax Wire, and regulated by thevvalve 13. The investment being porous, the metal more porous and thereby offering less resistance to the influence of the pressure within the reservoir. The cup 12 is permitted to re-l main within the cup 24 and is used as a crucible for the metal, the character of pressure being optional, and the cup 12 preferably omitted when casting with compressed air.

The formation of the investment and the preliminary steps taken to secure the mold oi' pattern when casting with compressed air are the same as before described. The suction pump 7 is replaced by a force pump and the reservoir filled with compressed air. The Hexible tube 2O is 'connected to the tube'9 and the cup 14 is placed over the cup 12 when placed in the support block 16. The air pressure is regulated by the valve 13 and molten metal introduced into the opening left by the wax 4or metal sprue is driven into the cavity or'niold with sufficient force to reproduce the inlay or pattern in met-al, the air penetratingthe porous investment material and escaping through the stem into the openi ing in the block 16 (see Fig. 2) or through the opening 28 when the investing ring 22 is used. c.

The pressure in the reservoir when `using compressed air or vacuum is ascertained by the gage 4 andthe operator is thereby enabled to accurately regulate the outward iniuence of pressureexerted upon theinvestment or mold Within the cup.

Having thus described the invention, what is claimed as-neW is:

l. An apparatus for use in casting metal dentures, including a chamber, a tube entering the same, means for .exhausting air or compressing air into said chamber, a pressure gage connected to the chamber, a pipe extending from said chamber havingtherein a regulating valve, the exterior and interior faces of the end of said-.pipe being ground to form a joint, and an investment cup having a connection to said chamber. through said joint.

2.v A'n apparatus for use in casting metal dentures, including a chamber, an IJinlet tube enteringv the chamber, an air pump fitting within said tube, apiessure gage connected` to the chamber, ya pipe extending from said chamber having therein a controlling valve,

the exterior and interiorfaces of the end of said pipe being ground to form a joint,.and an investment cup having a eonnecti'on to isiv said chamber through said joint, said inchamber wherein the pressure of the contained air may be varied, a tube extending from said chamber, and al flexible pipehaving expanded ends internally ground, the external face of the end of the first named tube being ground to fit the expanded end i of said iiexible pipe, and the interior ace of the end of the tube being ground to fit the ground face of the stem on said investment Cup' l 5. The combination wlth an investment cup comprising a bowl--shaped body having an exterior ground Jface ait its upper end'and a-tapering tubular stem also having a ground face, of an investment ring comprising a hollow metallic cylinder fitting within the bowl-shaped body of the investment cup but removable therefrom, said cylinder having openings for the escape of air at one end, and the exterior face of the other end of the cylinder being ground to form a vground joint with said bowl-shaped body.

6. In an apparatus for usein casting metal dentures, a cylindrical chamber, an inlet tube leading into the same and connected with an air pump for exhausting or coinpressing air withinthe cylinder, a controlling valve for said inlet tube, an outlet pipe, a controlling valve therefor, the end of said outlet pipe being exteriorly and interiorly ground, an investment cup having a bowlshaped body and a tubular tapered stem, the exterior and interior faces of the bowlshaped body being ground, and the exterior face of the stem being ground, a cap adapted to t over the bowl-shaped body and having an interior ground tace, and a tube connected with the cap and having at one end an enlargement adapted to it over the end of the tube leading from the air chamber.

7. ln an apparatus for use in casting metal dentures, an outer investment cup comprising a bowl shaped body having a tapering stem, and an inner cup adapted to be contained within the outer cup and to form a Crucible for the metal to be cast in `said outer cup, said inner cup having a bowl shaped body and' a tubular tapering stem,

in combination with a chamber, an inlet tube entering the chamber, an air pump connected to said tube and a pipe extending from said chamber having therein a controlling valve, the extremity of such pipe being adapted to t over the end of the investment cup.

In testimony whereof l aHx my signature in presence of two witnesses.

" ELZA R. STEALY.A

W. J., SEELEY, 

